//
// Created by yangchao on 2022/6/9.
// 141. 环形链表: https://leetcode.cn/problems/linked-list-cycle/
//

#include "../DataStructure/ListNode.h"

class HasCycle {
public:
    bool hasCycle(ListNode* head) {
        if (head == nullptr || head->next == nullptr) return false;
        ListNode* slow = head;
        ListNode* fast = head->next;
        while (slow != fast) {
            if (fast == nullptr || fast->next == nullptr) return false;
            slow = slow->next;
            fast = fast->next->next;
        }
        return true;
    }
};
